Theory and Practice for Environmental Risk Assessment: Understanding the Trade-Off Between the Benefits and Risks Behind Herbicide Use as Tool for Designing Sustainable Weed Management Systems

PESSAH, SEBASTIAN; DUARTE VERA, ALEJANDRA; GHERSA, FELIPE; FERRARO, DIEGO OMAR

Decision Support Systems for Weed Management

Springer International Publishing

Año: 2020; p. 161 - 189

The adoption of herbicides as a weed control strategy has allowed farmersto reduce the short-term effects of biological adversities on crop yields. However,they have also jeopardized agroecosystem sustainability by causing negative alterationsof social and environmental subsystems. The physicochemical properties ofherbicides (volatility, adsorption, or water solubility) can make them persist in thesoil, air, and water, changing the structure and function of key environmental compartments.The occurrence of herbicide-resistant weed populations has generated apositive feedback loop requiring the application of higher doses, aggravating negativeexternalities. Hence, the economic benefits of herbicides as a unique controlstrategy substantially decrease in time. In addition, the dependence of agriculturalsystems on external inputs generates an herbicidal ?lock-in? process that hinders thetransition towards more sustainable integrated management systems. Therefore,there is a pressing need to elucidate the principal aspects of environmental riskanalysis of herbicide use in agroecosystems. The objectives of this chapter are: (1)to introduce key concepts related to the construction and application of environmentalrisk indicators with a focus on agricultural system risk assessment, (2) to list thepotentially negative effects associated with the use of herbicides, (3) to understandthe processes that regulate herbicides? fate and behavior in farming systems, (4) tohighlight the importance of decision support systems (DSS) in reducing herbicideuse in favor of integrated weed management (IWM), and (5) to understand thedecision-makinglogic behind the increasing adoption of chemical weed controldespite its negative socio-environmental effects.